DG Flugzeugbau DG-1000T Maintenance Manual page 59

5. Check both carburettors independently:
Remove the carburettor cover and membrane, remove the needle valve, flush
the carburettor by switching on the fuel pump. The fuel must spout out as a
powerful stream. If a large amount of fuel leaks out of the carburettor when
you remove the membrane this is a sign that:
a) a dirt particle prevents the needle valve from closing completely.
b) the main nozzle is clogged (dirty), so that the engine can't receive the full
amount of fuel. In this case you have to disassemble the main nozzle and to
clean its chamber, see sect. 1.13.7.2 item 2.
c) Check the connection of the throttle cable for damage and wear.
6. Primer
a) Check the filter of the primer valve. The filter is installed in the fuel
distributor in which the primer valve is inserted. Loosen the hose clamps and
the mounting bolt of the distributor and pull out the primer. Flow fuel
through the filter in reverse direction and check that as the fuel comes out of
the filter any dirt is removed. In addition flow fuel in reverse direction
through that outlet of the multiple-connector where the excess fuel line
restriction is installed. Reinstall the connector.
b) Check the function of the primer valve and nozzle (engine must be cold).
Switch the primer switch in auto position. Remove the air intake filter.
Enter the DEI-NT set up menu and set primer test Y, then switch on the
ignition and press the starter button. Now the DEI-NT must display a syringe
on the centre display and fuel must be injected via the nozzle into the intake
manifold of the carburettor without the starter motor operating.
Warning: Test only for 2-3 seconds, otherwise you may flood the engine.
Enter the DEI-NT set up menu and reset to primer test N, otherwise the
starter motor will not function.
c) Check the hoses which connect the primer valve to the carburettors for any
damage.
d) Leak test of the primer valve: with the ignition on (fuel pump running) fuel
must not be injected.
7. Check all fuel lines for any wear, kinks, tight fit and leaks. Check especially
the fuel lines in the engine compartment, switch on the ignition to run the
fuel pump.
Issued: July 2017 TN1000/32
Maintenance Manual DG-1000T
3.6